Vault Decay Prediction Formula for Posterior Chamber Phakic Intraocular Lens With Central Hole Implantation: A...

To evaluate the long-term clinical outcomes of the implantable collamer lens (ICL) V4c and to develop a predictive formula for vault decay over a 10-year postoperative period.

Retrospective observational case series.

Forty-seven eyes from 26 patients who underwent ICL V4c implantation for the correction of myopia and myopic astigmatism.

Safety, efficacy, predictability, stability, and complications were assessed over a 10-year follow-up. Vault was measured using anterior segment optical coherence tomography.

Logarithm of the minimum angle of resolution (logMAR) uncorrected and corrected distance visual acuity (UDVA and CDVA), spherical equivalent (SE) refraction, intraocular pressure (IOP), endothelial cell density (ECD), and vault.

At 10 years postoperatively, mean logMAR UDVA and CDVA were -0.02 ± 0.15 and -0.18 ± 0.09, respectively. The safety and efficacy indices were 0.95 ± 0.20 and 0.67 ± 0.21, respectively. SE predictability showed that 82.6% and 89.1% of eyes were within ±0.5 D and ±1.0 D of the attempted correction, respectively. Mean IOP remained stable (14.8 ± 3.4 mmHg preoperatively vs. 15.4 ± 3.1 mmHg at 10 years). Mean ECD loss was 6.8% over 10 years. Vault kinetics analysis led to the development of a 3-component exponential model for predicting long-term vault decay. No cases of pigment dispersion glaucoma, pupillary block, or other vision-threatening complications were observed.

ICL V4c implantation demonstrates excellent long-term safety, efficacy, and predictability. Moreover, vault behavior-a key safety indicator-can be reliably predicted using a novel mathematical model.